Waste and/or residual streams of low or negative value produced in refineries and petrochemical plants have typically posed a problem for re-use or disposal. A common suggestion is to use the waste streams for their heating value in combustion processes. Examples include vent gas containing hydrocarbons, carbon dioxide, carbon monoxide and steam; metal-containing sludges and gums; hydrocarbon-in-water emulsion streams (e.g. from petroleum emulsion breaking and dewatering); aromatic solvent-containing streams; spent caustic streams; coal dust slurdes; decoking offgas; coke solids; and the like. However, such streams are typically classified as hazardous waste. Disposal of streams so classified often requires extensive management to minimize adverse environmental impact. Thus, the benefits to be obtained by burning such streams are limited by the costs imposed by management requirements.
A high temperature combustion process is known for obtaining clean, environmentally acceptable heating value from waste streams which are otherwise difficult and expensive to dispose. In this high temperature process, feed to the high temperature flame is mixed with a nearly stoichiometric amount of oxygen and injected into the combustion zone wherein the hydrocarbons in the feed are burned to form primarily carbon dioxide and water at a temperature of 3000.degree. F. Heat produced is then recovered for utilities production.
Several drawbacks to the above process have been experienced. For example, waste stream production in a plant typically varies extensively as to rate and composition. Where the hydrocarbon to oxygen ratio fluctuates quickly, too much hydrocarbon results in the formation of soot, whereas too little hydrocarbon causes the flame to go out. Complicated measures must generally be undertaken to smooth out these variations in the feed, usually elaborate blending systems and redundant feed systems.
Conversion of a hydrocarbon feed to a synthesis gas containing carbon monoxide for methanol production and/or hydrogen for ammonia production, hydrogenation and other uses is well known in the art. A hydrocarbon stream is converted usually in the presence of steam at an elevated temperature to produce carbon monoxide and hydrogen. It is also known that carbon monoxide reacts with steam at an elevated temperature in a shift reaction to produce additional hydrogen.
It would be advantageous to be able to convert diversely composed low value hydrocarbon process streams into one or more valuable product streams such as hydrogen and/or syngas (H.sub.2 +CO) to avoid the production of waste streams. In addition, it would be advantageous if the conversion process had the versatility to handle feeds of varying composition in continuous operation without upset. Further, it would be advantageous to operate a transport conversion reactor at a relatively low temperature, with reduced oxygen consumption and enhanced efficiency.